Effect of Si addition on microstructure and properties of magnesium alloys with high Al and Zn contents

• Published in: Vacuum Vol. 141; pp. 144 - 151
• Main Authors: Wang, M., Xiao, D.H., Liu, W.S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2017
• Subjects: Corrosion behavior; Degradable magnesium alloys; Mechanical properties; Microstructure; Mechanical properties; Degradable magnesium alloys; Microstructure; Corrosion behavior
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2017.04.005

In order to assess the possibility of using magnesium alloys with high Al and Zn contents as degradable fracturing balls, the effects of Si addition on microstructures, mechanical properties and degradable behavior of Mg-17Al-5Zn (mass.%) alloy were investigated. The results show that the minor Si addition can refine α-Mg matrix and modify Mg2Si particles. With the increase of Si content, the yield strength of the alloys initially increases and reaches to the maximum 309 MPa in alloy containing 0.5 wt % Si. The degradable corrosion rate exhibits an inverse trend and reaches the maximum in alloy containing 3 wt % Si with 0.46 mm/day at 298 K and 5.39 mm/day at 366 K, respectively. •The Mg-Al-Zn-Si alloys with high Al and Zn contents were firstly investigated.•Fine and uniformly-distributed Mg2Si particles hinder the grain growth, resulting in the refined α-Mg matrix grains and more compact network β-Mg17Al12 phases in the Si-containing alloys.•Si addition improves the mechanical properties of the alloys due to fine grain strengthening of α-Mg grain and second phase strengthening of fine Mg2Si.•Si addition affects the corrosion behavior of the alloys, due to the formation of coarse polygonal and dendrite Mg2Si.